support ebpf

component/ebpf/ebpf_linux.go

@@ -0,0 +1,112 @@
+package ebpf
+
+import (
+	"fmt"
+	"net/netip"
+
+	"github.com/vishvananda/netlink"
+
+	"github.com/Dreamacro/clash/common/cmd"
+	"github.com/Dreamacro/clash/component/dialer"
+	"github.com/Dreamacro/clash/component/ebpf/redir"
+	"github.com/Dreamacro/clash/component/ebpf/tc"
+	C "github.com/Dreamacro/clash/constant"
+)
+
+// NewTcEBpfProgram new redirect to tun ebpf program
+func NewTcEBpfProgram(ifaceNames []string, tunName string) (*TcEBpfProgram, error) {
+	tunIface, err := netlink.LinkByName(tunName)
+	if err != nil {
+		return nil, fmt.Errorf("lookup network iface %q: %w", tunName, err)
+	}
+
+	tunIndex := uint32(tunIface.Attrs().Index)
+
+	dialer.DefaultRoutingMark.Store(C.ClashTrafficMark)
+
+	ifMark := uint32(dialer.DefaultRoutingMark.Load())
+
+	var pros []C.EBpf
+	for _, ifaceName := range ifaceNames {
+		iface, err := netlink.LinkByName(ifaceName)
+		if err != nil {
+			return nil, fmt.Errorf("lookup network iface %q: %w", ifaceName, err)
+		}
+		if iface.Attrs().OperState != netlink.OperUp {
+			return nil, fmt.Errorf("network iface %q is down", ifaceName)
+		}
+
+		attrs := iface.Attrs()
+		index := attrs.Index
+
+		tcPro := tc.NewEBpfTc(ifaceName, index, ifMark, tunIndex)
+		if err = tcPro.Start(); err != nil {
+			return nil, err
+		}
+
+		pros = append(pros, tcPro)
+	}
+
+	systemSetting(ifaceNames...)
+
+	return &TcEBpfProgram{pros: pros, rawNICs: ifaceNames}, nil
+}
+
+// NewRedirEBpfProgram new auto redirect ebpf program
+func NewRedirEBpfProgram(ifaceNames []string, redirPort uint16, defaultRouteInterfaceName string) (*TcEBpfProgram, error) {
+	defaultRouteInterface, err := netlink.LinkByName(defaultRouteInterfaceName)
+	if err != nil {
+		return nil, fmt.Errorf("lookup network iface %q: %w", defaultRouteInterfaceName, err)
+	}
+
+	defaultRouteIndex := uint32(defaultRouteInterface.Attrs().Index)
+
+	var pros []C.EBpf
+	for _, ifaceName := range ifaceNames {
+		iface, err := netlink.LinkByName(ifaceName)
+		if err != nil {
+			return nil, fmt.Errorf("lookup network iface %q: %w", ifaceName, err)
+		}
+
+		attrs := iface.Attrs()
+		index := attrs.Index
+
+		addrs, err := netlink.AddrList(iface, netlink.FAMILY_V4)
+		if err != nil {
+			return nil, fmt.Errorf("lookup network iface %q address: %w", ifaceName, err)
+		}
+
+		if len(addrs) == 0 {
+			return nil, fmt.Errorf("network iface %q does not contain any ipv4 addresses", ifaceName)
+		}
+
+		address, _ := netip.AddrFromSlice(addrs[0].IP)
+		redirAddrPort := netip.AddrPortFrom(address, redirPort)
+
+		redirPro := redir.NewEBpfRedirect(ifaceName, index, 0, defaultRouteIndex, redirAddrPort)
+		if err = redirPro.Start(); err != nil {
+			return nil, err
+		}
+
+		pros = append(pros, redirPro)
+	}
+
+	systemSetting(ifaceNames...)
+
+	return &TcEBpfProgram{pros: pros, rawNICs: ifaceNames}, nil
+}
+
+func systemSetting(ifaceNames ...string) {
+	_, _ = cmd.ExecCmd("sysctl -w net.ipv4.ip_forward=1")
+	_, _ = cmd.ExecCmd("sysctl -w net.ipv4.conf.all.forwarding=1")
+	_, _ = cmd.ExecCmd("sysctl -w net.ipv4.conf.all.accept_local=1")
+	_, _ = cmd.ExecCmd("sysctl -w net.ipv4.conf.all.accept_redirects=1")
+	_, _ = cmd.ExecCmd("sysctl -w net.ipv4.conf.all.rp_filter=0")
+
+	for _, ifaceName := range ifaceNames {
+		_, _ = cmd.ExecCmd(fmt.Sprintf("sysctl -w net.ipv4.conf.%s.forwarding=1", ifaceName))
+		_, _ = cmd.ExecCmd(fmt.Sprintf("sysctl -w net.ipv4.conf.%s.accept_local=1", ifaceName))
+		_, _ = cmd.ExecCmd(fmt.Sprintf("sysctl -w net.ipv4.conf.%s.accept_redirects=1", ifaceName))
+		_, _ = cmd.ExecCmd(fmt.Sprintf("sysctl -w net.ipv4.conf.%s.rp_filter=0", ifaceName))
+	}
+}